Embolic Delivery

ABSTRACT

Concepts related to embolic delivery, including embolic detachment systems and an embolic pusher retention mechanism/system are discussed.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 62/564,952 filed Sep. 28, 2017 entitled Embolic Delivery, which ishereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Embolic material—including embolic coils and embolic meshes are used fora variety of occlusive therapeutic purposes in the vasculature, such as,but not limited to, occluding aneurysms, vessel shutdown, left atrialappendage occlusion, treating arteriovenous malformations and fistulas,and fallopian tube occlusion. These embolic materials can beparticularly small especially when used in the neurovasculature—forinstance, when used to treat neurovascular aneurysms. A relatively newercategory of embolic material known as intrasaccular devices generallycomprises meshes that conform to the shape of a portion of the treatmentsite to promote occlusion. These embolic devices are generally deliveredvia a pusher that the embolic material is connected to, where the pusheris pushed through a delivery catheter and a detachment system thendetaches the embolic material from the pusher.

Detaching the embolic material from the pusher upon delivery can becomplicated, especially as these embolic or occlusive devices are sizeddown to treat smaller target regions. Another problematic area involvesthe situation when the embolic material is pushed out from the deliverycatheter and adopts its natural expansile shape, which can createdelivery problems—including kickback and high delivery force—due to thesudden shape change which the implant adopts. The following embodimentsdeal with systems, devices, and methods that address these issues.

SUMMARY OF THE INVENTION

In one embodiment, an occlusive device and/or an occlusive system isdescribed. The proximal end of the occlusive device is connected to aconnection interface attached to a delivery pusher, and wires of theocclusive device are wound around the connection interface.

In one embodiment, an occlusive device and/or an occlusive system isdescribed. The proximal end of the occlusive device is connected to aconnection interface attached to a delivery pusher. The connectioninterface includes one or more bands and the occlusive device isconnected to the bands of the connection interface.

In one embodiment, an occlusive device and/or an occlusive system isdescribed. The proximal end of the occlusive device is connected to aconnection interface attached to a delivery pusher. The connectioninterface includes one or more openings that accommodates the occlusivedevice. In one embodiment, the connection interface additionallyincludes various cut-out regions to augment the flexibility of theconnection interface.

In one embodiment, an occlusive device and/or an occlusive system isdescribed. The proximal end of the occlusive device is connected to aconnection interface attached to a delivery pusher. The connectioninterface includes one or more coils spanning around the connectionstructure, and the occlusive device is connected to portions of the oneor more coils.

The following embodiments deal with a delivery and detachment systemthat can be used with embolic occlusive material, includingintrasaccular devices.

In one embodiment, an occlusive device and/or an occlusive system isdescribed. The occlusive device is connected to a delivery pusher andthe distal portion of the delivery pusher has a heat-set floweringexpanded shape.

In one embodiment, an occlusive device and/or an occlusive system isdescribed. The occlusive device is connected to a delivery pusher and amechanical severing mechanism can be tracked through the delivery pusherto detach the occlusive device from the delivery pusher.

In one embodiment, an occlusive device and/or an occlusive system isdescribed. The occlusive device is connected to a delivery pusher and athermal severing mechanism can be tracked through the delivery pusher todetach the occlusive device from the delivery pusher.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of which embodiments ofthe invention are capable of will be apparent and elucidated from thefollowing description of embodiments of the present invention, in which:

FIG. 1a illustrates an embolic delivery device, according to oneembodiment.

FIG. 1b illustrates an embolic delivery device within a deliverycatheter, according to one embodiment.

FIG. 2 illustrates a connection interface between a delivery pusher andan embolic device, according to one embodiment.

FIG. 2a illustrates a connection interface between a delivery pusher andan embolic device, according to one embodiment.

FIG. 2b illustrates a connection interface between a delivery pusher andan embolic device, according to one embodiment.

FIG. 3 illustrates a connection interface between a delivery pusher andan embolic device, according to one embodiment.

FIG. 4 illustrates a connection interface between a delivery pusher andan embolic device, according to one embodiment.

FIG. 4a illustrates a connection interface between a delivery pusher andan embolic device, according to one embodiment.

FIG. 4b illustrates a connection interface between a delivery pusher andan embolic device, according to one embodiment.

FIG. 5 illustrates a connection interface between a delivery pusher andan embolic device, according to one embodiment.

FIG. 6a illustrates attachment locations between a connection interfaceand a delivery pusher, according to one embodiment.

FIG. 6b illustrates a connection interface, intermediate structure, anddelivery pusher, according to one embodiment.

FIG. 6c illustrates a connection interface, intermediate structure, anddelivery pusher, according to one embodiment.

FIG. 7 illustrates a delivery pusher in a collapsed state, according toone embodiment.

FIG. 8 illustrates a cross-sectional view of a delivery pusher,according to one embodiment.

FIG. 9 illustrates a flattened view of a delivery pusher, according toone embodiment.

FIG. 10 illustrates a delivery pusher in an expanded state, according toone embodiment.

FIG. 11 illustrates a delivery pusher in a collapsed state connected toan occlusive device in a collapsed state, according to one embodiment.

FIG. 12 illustrates a delivery pusher in a collapsed state connected toan occlusive device in a partially expanded state, according to oneembodiment.

FIG. 13 illustrates a delivery pusher in an expanded state connected toan occlusive device in an expanded state, according to one embodiment.

FIG. 14 illustrates a delivery pusher and a mechanical severingmechanism used to detach an occlusive device.

FIG. 15 illustrates a delivery pusher and a heater used to detach anocclusive device.

DESCRIPTION OF EMBODIMENTS

Specific embodiments of the invention will now be described withreference to the accompanying drawings. This invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art. Theterminology used in the detailed description of the embodimentsillustrated in the accompanying drawings is not intended to be limitingof the invention. In the drawings, like numbers refer to like elements.

Embolic or occlusive devices are used for a variety of interventionalpurposes, for instance occluding or filling a target treatmentspace—such as an aneurysm, left atrial appendage, fistula, or vessel—inorder to limit blood flow to the region. A certain class of embolicmaterial called intrasaccular devices typically utilizes meshes toconform to the shape of the neck or ostium of the treatment site (e.g.,aneurysm) to better occlude the treatment site to thereby limit bloodflow to the region and better promote clotting over time.

For neurovascular procedures, such as occluding neurovascular aneurysms,unique complications are involved. The neurovascular blood vessels aresmall, and the embolic devices must also be small—first to fit within acatheter small enough to access the neurovascular vessels, and second tofit the relatively small target treatment sites. Creating usable embolicdevices with this smaller environment in mind can be challenging for avariety of reasons. For instance, when the occlusive devices aredelivered from a delivery catheter and adopt their heat set, expansileshape, significant force is generated which makes delivery difficult.Moreover, it can be difficult to design a detachment system to detachthe occlusive device from the delivery pusher, especially as theseocclusive devices are sized smaller to treat smaller vessels and smallertarget areas. The following embodiments address these issues.

FIGS. 1a-1b illustrate an occlusion system 100 having an occlusivedevice 106 connected to a delivery pusher 102. The pusher 102 is used todeliver the occlusive device 106 through a catheter 108 and distallybeyond the catheter to be delivered to a target treatment location. Thedistal end of the delivery pusher 102 is attached to a connectionstructure or connection interface 104 which connects to the occlusivedevice 106. In this way, the proximal end of the connection interface104 is connected to the distal end of the delivery pusher 102, while thedistal end of the connection interface 104 is connected to the proximalend of the occlusive device 106. The occlusive device 106 adopts acontracted, elongated configuration when housed in a delivery catheter(as shown in FIG. 1b ) and its heat-set, expanded configuration when notwithin the delivery catheter (as shown in FIG. 1a ). The delivery pusher102 is typically quite long, at least as long as the delivery catheter108 since the pusher is pushed through the entirety of the deliverycatheter. For instance, for a neurovasculature procedure, the cathetermust track a distance between the femoral artery (the typical entrypoint for such procedures) up into the neurovascular arteries, which canspan several feet—so the pusher and catheter, for instance, can be100-160 cm in length.

Occlusive device 106 can take on a variety of configurations, such as anocclusive intrasaccular mesh or an embolic coil. In one embodiment, theocclusive device is an intrasaccular device comprising a mesh ofmetallic wires—made of, for instance, nitinol, stainless steel, and/orradiopaque material such as tantalum, platinum, gold, or palladium. Inanother example, drawn-filled tubing, which comprises a radiopaque corematerial surrounded by a metallic (e.g., nitinol or stainless steel)jacket can be used as part of the metallic mesh to further aid invisualizing the occlusive device. Intrasaccular devices, includingvarious intrasaccular embodiments, are described in US PublicationNumbers 20141200607 and 20170224355, and U.S. Pat. Nos. 9,597,087,9,918,720, 9,629,635, 9,955,976, 9,078,658, 9,198,670, 9,295,473, and9,492,174—all of which are hereby incorporated by reference in theirentirety, and all/any of which can be used as examples of occlusivedevices delivered by the inventive devices/systems disclosed herein.

With typical intrasaccular devices, the proximal end of the device iswelded directly to the pusher end, and some detachment means (e.g.,thermolytic, electrolytic, or mechanical) are used to sever theocclusive device from the delivery pusher so that the occlusive devicecan be deployed. In practice, this would mean the wires comprising theproximal end of the occlusive device are welded directly to the interioror exterior of the pusher. Often, this involves a cylindrical radiopaquemarker band attached at the distal end of the pusher, and the occlusivedevice proximal end wires being welded directly to the interior orexterior of this marker band. This marker band helps in visualizing theproximal part of the device and also provides an attachment point forthe occlusive device. One problem with this welding approach is that thewires comprising the occlusive device have no freedom of movement whenattached in this manner. The attachment junction between the proximalend wires of the occlusive device and the pusher are high stress areasand therefore as the wires adopt their naturally heat set, expandedshape upon being released from the delivery catheter, there is a lot offorce being generated in a relatively small area. Therefore, as theocclusive device adopts its expanded shape, the delivery force is quitehigh. As a result, the user must push hard to get the occlusive deviceto exit the catheter, and there is often a lot of kickback as the deviceis being deployed. This kickback can be unpleasant for theoperator/surgeon and can also result in the implant being improperlydeployed. This fixed attachment structure also makes retraction backinto the delivery catheter difficult, for instance, in circumstanceswhere the implant needs to be repositioned.

FIGS. 2-5 show various connection interface embodiments between theproximal end of the occlusive device 106 and the pusher 102 which allowsome “give” or movement of the proximal end of the occlusive device todistribute the delivery force and thereby minimize the associateddelivery forces to avoid the complications discussed above. As mentionedabove, the occlusive device 106 can be a metallic mesh comprising aplurality of wires—so the wires at the proximal end of the occlusivedevice 106 are connected to or linked to the connection interface.

In one embodiment, shown in FIG. 2, the connection interface 104 is athin ring and the wires 110 of the proximal or attached end of theocclusive device 106 are pulled around the ring such that the wires arelooped or wrapped around the ring. This is done by pulling the wirebehind the connection interface 104, then pulling the wire around theconnection interface 104, and then pulling the wire in front of theconnection interface 104—the end resulting being that a portion of thewire sits behind the connection interface. This is shown in FIG. 2a ,where a portion 110 c of wire 110 sits over a first side of theconnection interface 104 (e.g., distal of the connection interface) anda portion 110 d of the wire sits over a second side of the connectioninterface 104 (e.g., proximal of the connection interface). In this way,the wire of the occlusive device is secured to the connection interface104, but in a way where the wire still has some degree of freedom ofmovement relative to the connection interface 104 since it is notattached to the connection interface.

Connection interface 104 is then attached to delivery pusher 102,however it is attached in such a way as to allow freedom of movement ofthe wires 110 of occlusive device 106. For instance, connectioninterface 104 is attached to the distal end of the pusher (e.g. throughwelding, adhesives, or other mechanical attachment means/structures)however these attachment points 120 are located in the spaces 109between the wires 110 forming the proximal end of occlusive device 106.In this way, the wires 110 are not directly bonded to the pusher andthereby have some freedom of movement. FIG. 6a shows this configurationand can be thought of as the view directly behind the end of theconnection interface 104 that is attached to delivery pusher 102—wherethe attachment points 120 are spread out in various locations along theconnection interface. The attachment means can take on a variety offorms, including, for example, welding, adhesive, and/or othermechanical concepts. Due to this freedom of movement, as the occlusivedevice 106 is delivered from delivery catheter 108 and adopts itsexpanded shape, the occlusive device has some degree of give to reducesome of the delivery force, making deployment from the delivery catheterand retraction back into the delivery catheter (if needed) much easier.

Other attachment means between the delivery pusher 102 and connectioninterface 104 are also contemplated. For instance, both the deliverypusher 102 and connection interface 104 can include a plurality of holesaround the periphery of each, where tethers are connected between thesesets of holes so that the delivery pusher 102 and connection interface104 are connected, but in a manner that still allows movement of wires110. Alternatively, a plurality of small mechanical rods can be placedbetween the delivery pusher 102 and connection interface 104 andattached to each, these rods are circumferentially positioned around theproximal end of connection interface 104 and distal end of pusher 102,so as to mechanically bind the two structures, but again in a way thatallows movement of wires 110.

Different embodiments of the connection interface 104 can utilizevarious shape geometries to further enable enough space between thepusher and the connection interface to allow movement of the wires 110,given a segment of the wires 110 are in between the connection interface104 and the pusher. In one embodiment, the proximal part of theconnection interface 104 (the part of the connection interface 104closest to pusher 102) has a number of inwardly curved or indented faces(e.g., forming a wavy shape) to allow more room for the wires 110. Inone embodiment, the connection interface 104 takes the form shown inFIG. 2b where a portion of the connection interface projects inwardlyinto pusher 102. The connection interface 104 still comprises a ringshape, however a curved arc wire segment 104 b proximally connects tothe connection interface, projects inwardly into the pusher 102 and isattached to part of the pusher 102—in this way, the pusher 102 andconnection interface 104 are connected through curved segment 104 b.There is still a gap 104 c between the connection interface 104 anddelivery pusher 102, and the wires 110 of the occlusive device sitwithin this gap in the manner shown in FIGS. 2-2 a. In this way, thewires have freedom of movement between the pusher 102 and connectioninterface 104. Different embodiments can utilize, for instance, aparabolic sheet having the topographical profile of the connectioninterface and curved segment 104 b, where holes are cut into the sheetto accommodate wires 110. Other embodiments can utilize another similarattached, projecting structure 104 b between the connection interface104 and delivery pusher 102 which projects into the delivery pusher 102and is attached to both the delivery pusher 102 and the connectioninterface 104. Again, the point here is to allow the wires to have somefreedom of movement by providing space between the connection interface104 and delivery pusher to accommodate a portion of wires 110. Thisfreedom of movement will help minimize frictional and other forcesduring deployment of the implant, making implant delivery easier.

In another related embodiment shown in FIG. 3, the proximal end wires110 of the occlusive device are connected directly onto rotatable bands112. The bands have an inner diameter slightly larger than the outerdiameter of the connection interface ring 104 and are not attached tothe connection interface 104 and can therefore independently rotate overthe connection interface 104. The wire ends 110 are directly connected(for instance, by welding or adhesive) to the rotatable bands 112. Theconnection interface 104 is attached to the distal end of the deliverypusher in such a way as to allow rotation of the bands, for instance byattaching the connection interface to the delivery pusher at locations111 between the rotatable bands 112 (e.g., via welding, adhesive,mechanical rod structures, or other means) to enable free rotation ofthe bands. FIG. 6a , again, offers an example of how these attachmentpoints can be spread around the connection interface 104. The embodimentof FIG. 2b can also be utilized as a way to connect the delivery pusherand the connection interface, where the bands would be mounted to theconnection interface and the gap 104 c would allow the bands to rotatefreely; alternatively the connection interface 104 could be indented(e.g, forming a wavy shape), as discussed above, to allow room for thewires between the connection interface and delivery pusher. As theocclusive device 106 is freed from the delivery catheter, the proximalend of the occlusive device will be allowed to move since the proximalend wires 110 are connected to the rotating bands 112—thereby reducingsome of the delivery force and ensuring an easier deployment anddelivery. The rotating bands can be considered as a retention structure,retaining the wires while also allowing movement of the wires due to theability of the bands to rotate over the connection interface 104.

Another related embodiment similar to the one shown in FIG. 3 would nothave the proximal end of the wires connect to rotatable bands 112.Instead, the rotatable bands would contain a plurality of holes, and thewires would enter one hole, exit another hole and then continue to bewound back into the occlusive device—in this way, a portion of the wireis retained within the rotatable band.

Another related embodiment is shown in FIG. 4, where the connectioninterface 104 a is a flexible wire or tube with several cuts 114 boredinto the surface (e.g., by laser, etching, mechanical cuts, or othermeans), where these cuts offer a flexible surface so the interface 104 acan bend or make slight movements in response to force. The interface104 a also includes several holes 116, these holes accommodate theproximal end wires of the occlusive device, where the wires are bondedto the holes (for instance, by welding). These holes 116 can beconsidered as a retention structure used to retain the wires. In oneexample, each wire is positioned within a hole such that the proximalend of each wire terminates within its own, separate hole. Each wire canhave an enlarged end which is contained within the hole, or each wireend can be mechanically affixed (e.g. through adhesive) within the hole.Another wire would then terminate in another hole. This configuration isshown in FIG. 4a where a first occlusive device proximal end wire 110 aterminates in hole 116 a of connection interface 104 a, while anotherocclusive device proximal end wire 110 b terminates in hole 116 b. Theholes that the wires terminate in can either be adjacent ornon-adjacent, depending on factors including the size of the occlusivedevice, the number of wires used to wind the occlusive device, and thesize of the connection interface. In another example, the wire ispositioned through two holes such that the wire end is first placed in afirst hole and then pulled out from a second hole. In this example aportion of the wire would physically sit underneath element 104 a beforetracking back out through another hole and then being wound back intothe occlusive device. The wire could be pulled back out through eitheran adjacent hole, or a non-adjacent hole. This configuration is shown inFIG. 4b where a wire forming the proximal end of the occlusive device ispulled through hole 116 a and out another hole 116 b—in this manner, thewire is secured to the connection interface 104 a by nature of beingwound within and through a portion said connection interface. Varioushole configurations are possible, for instance the holes can sit along aplurality of rows (or alternately, sit along various haphazard portionsof the connection interface) and the wire can enter a hole of a firstrow, track through a portion of the connection interface, and exit ahole of another row—in this manner, a portion of the wire would beretained within part of the connection interface. In another example,the wire is tracked through the hole at the front end of the connectioninterface, through another hole behind the connection interface, andthen back through another set of holes through the connection interfacesuch that the wire ends up in front of the connection interface—in thismanner, a portion of the wire would be retained behind the connectioninterface and another portion of the wire would be retained within theconnection interface. The connection interface 104 a is pulled into acircular ring shape where the two ends are welded together to produce acircular or ring-like connection interface shape like the ones shown inFIGS. 2-3. The interface 104 a is then attached to the distal end of thedelivery pusher. One advantage of this configuration is that connectioninterface 104 a would not have to be connected at selected locations tothe delivery pusher since the cut-out sections 114 allow some slightmovement of the connection interface 104 a and associated wiresconnected to the interface—however, the connection interface 104 a couldalso be connected at selected intervals along the peripheral surface tothe delivery pusher to further augment the amount of flexibility as theocclusive device is delivered—similar to the configuration shown in FIG.6a and discussed earlier.

FIG. 5 offers another related embodiment where a connection interface104 similar to that of FIGS. 2-3 is used. A coil 118 is wound around theconnection interface 104 and the proximal occlusive mesh wire ends 110are connected to the coil. The coil has some freedom of movement due toits coiled shape and can therefore distribute some of the delivery forceas the associated occlusive device is delivered from the catheter. Thewire ends 110 are affixed to the coil, through various mechanical means(e.g., welding, mechanical ties, adhesive, bands, or clamps). Though thefigure shows the wire end as going past the coil, other embodiments canhave the wire end 110 affixed directly to the coil such that the wireend 110 is flush with said coil. Alternative embodiments can utilize thesegmented approach shown in FIG. 3 where various coils are placed aroundthe connection interface 104 (where the various coils would replace thevarious rotating bands 112 of FIG. 3). The one or more coils can beconsidered as a retention structure, connected to and retaining thewires of the occlusive device while also allowing the wires to move insome capacity during delivery from the overlying delivery catheter. Theconnection interface 104 is preferably connected to the distal end ofthe delivery pusher in a segmented circumferential manner as shown inFIG. 6a (e.g., via periodic spot welds, adhesive bonds, and/ormechanical rod structures spaced around the periphery of connectioninterface 104) so that the coil is not stuck against the delivery pusherand retains some independent movement. Alternative embodiments canutilize the wires 110 being connected to both the connection interface104 and the coil 118, or the wires 110 being connected directly to theconnection interface 104. In these alternative embodiments, the coilwill still have the ability to change shape (e.g., compress or elongate,both longitudinally and radially) to allow the wires to move a bit asthe occlusive device is delivered from the delivery catheter. Theconnection interface can utilize an indented or wavy profile, asdiscussed earlier, or utilize the configuration shown in FIG. 2b toprovide space between the connection interface and the deliverypusher—in these embodiments, the spaced attachment points of FIG. 6bwould not need to be utilized since there naturally is space between theconnection interface and the delivery pusher, and the wires of theocclusive device can fill all or part of this space.

Detachment means are also included in order to detach the occlusivedevice 106 from the delivery pusher 102. In one example, this detachmentsystem is placed between the connection interface 104 and the deliverypusher 102, so that the connection interface 104 and connected occlusivedevice 106 detach from the delivery pusher 102. Such detachment meansare well known in the art and can include mechanical, thermolytic,and/or electrolytic means. Thermolytic detachment systems are disclosedin U.S. Pat. Nos. 8,182,506, 9,414,819, 9,717,500, 8,932,317, 9,561,125,9,867,622—all of which are hereby incorporated by reference in theirentirety. These thermolytic systems typically utilize either a tetherand a heater to heat and sever the tether, or an adhesive and a heaterto melt the adhesive, and can be used to detach the connection interfacefrom the pusher. For example, the severable tether or meltable adhesivecan be placed between the connection interface 104 and the deliverypusher 102. Note, these concepts would typically utilize a tubulardelivery pusher with a lumen therein since a heater (such as a heatercoil) would sit within a distal section of the pusher lumen to melt orsever the attachment means (e.g., tether or adhesive) which are locatedin close proximity to the heater (e.g., abutting or next to the heater,or a tether which passes through the heater/heater coil).

In one example, one or more adhesive attachment points (like that shownin FIG. 6a ) are located between connection interface 104 and pusher102, the distal section of the pusher 102 lumen includes a heaterelement (e.g. heater coil) placed in close proximity to the adhesive(s)and the heat generated from the heater coil melts the adhesiveattachment points to separate the connection interface 104 from thepusher 102. In another example, a sacrificial intermediate structuresits between connection interface 104 and pusher 102. The connectioninterface is welded or otherwise attached to the intermediate structure.A degradable or severable medium (e.g. a tether or adhesive) is betweenthe delivery pusher and the intermediate structure, so that when theseverable medium severs or melts, the intermediate structure, connectioninterface 104, and occlusive device 106 all detach together from thedelivery pusher 102. With this concept, the connection interface 104would then be attached to the intermediate structure instead of thepusher, and the intermediate structure contains the severable mediumwhich enables the occlusive device 106 to detach from the deliverypusher 102. FIGS. 6b-6c show these embodiments. In FIG. 6b , connectioninterface 104 is proximally connected to intermediate structure 105 (forexample, via the spread connection points of FIG. 6a ), withintermediate structure 105 proximally connected to the delivery pusher102. A tether 122 spans a portion of the pusher and distally terminateswithin intermediate structure 105, where the tether connects theintermediate structure to the delivery pusher. Delivery pusher 102includes a heater (here, heater coil 124) which heats the tether tosever it to detach intermediate structure 105 and connection interface104 from the delivery pusher 102. In FIG. 6c , a similar setup is used,except a meltable adhesive 126 connects the delivery pusher 102 to theintermediate structure 105. The heater 124 functions to melt theadhesive 126, thereby detaching pusher 102 from intermediate structure105 and connection interface 104. Though not shown in FIG. 6b (but shownin FIG. 6c ), a pair of wires 128 a, 128 b span the pusher and distallyconnect to the heater 124 to power the heater (these wires areproximally connected to a voltage source, such as a battery). Theocclusive device is connected or otherwise linked to the connectioninterface 104, as described earlier, so that the occlusive device,connection interface 104, and intermediate structure 105 are alldeployed within the vasculature.

Note, the embodiments described above and shown in FIGS. 1-6 c generallyutilize a connection interface linked to the proximal part of anocclusive device in such a manner as to allow the proximal portion ofthe occlusive device—which interfaces with the connection interface—tohave some freedom of movement to make delivery of the occlusive deviceeasier as the occlusive device is delivered from the delivery catheter.In some embodiments, the connection interface can be considered asseparate from the delivery pusher where the connection interface anddelivery pusher are connected—in this manner, the delivery pusher andocclusive device are operatively (but not directly) connected such thatthe delivery pusher still pushes or pulls the occlusive device. In someembodiments, the connection interface can be considered as part of thedelivery pusher. For instance, where it is built directly onto thedistal portion of the delivery pusher, or where the distal portion ofthe delivery pusher is configured in such a manner to act as aconnection interface—an example of which would be creating a series ofsegmented channels around the pusher to leave room for the occlusivedevice wires as shown in FIG. 2, or than adding the rotating bandsand/or coils of FIGS. 3 and 5, respectively). In some embodiments, theconnection interface can be attached to the delivery pusher in alternateconfigurations—for instance, the connection interface can be placedradially over or radially within a distal portion of the delivery pusherrather than being attached to the distal end of the pusher.

Furthermore, in some embodiments (e.g., that of FIG. 2), the occlusivedevice and connection interface are connected or linked directly. Inother embodiments, the occlusive device and connection interface are notconnected directly, but rather linked indirectly through a retentionstructure (e.g. in FIG. 3 where wires 110 are connected to bands 112which are placed over connection interface 104). In these otherembodiments, though the connection interface and wires are not directlyconnected, they are operatively connected and linked through theretention structure.

Embolic delivery systems typically utilizing a mechanical deliverypusher connected to the embolic material, where some detachment means isused to detach the embolic or occlusive material from the deliverypusher. As the occlusive or embolic devices are sized down to treatsmaller vessels and smaller target areas (e.g., neurovascularaneurysms), creating a detachment system poses additional challengessince there is less room to work with. The following embodiments dealwith occlusive delivery concepts that address these issues.

FIG. 7 shows a delivery pusher 200 which connects to occlusive orembolic material (not shown here, though shown in later figures). Ratherthan showing the entire delivery pusher which can be long, the Figuresimply shows the distal part of the delivery pusher. The occlusive orembolic material can be a variety of devices—such as, but not limitedto, embolic coils and/or intrasaccular devices. FIG. 7 can be thought ofas the angled side view of a delivery pusher 200. A distal portion 202of the delivery pusher contains a plurality of arms 204, 205, 206, 207which are separated by a small cut-out region or channel 209 betweeneach arm. FIG. 8 offers a cross-sectional view from the front of thedistal portion 202 of pusher 200, where each arm 204-207 is visiblealong with a gap between each arm representing the cut-out region orchannel 209 between the various arms.

FIG. 9 shows the “rolled-out” view of FIG. 7; FIG. 9 can be thought ofas a flat plate with distal protruding arms 204-207, where the flatplate is later rolled into a cylindrical configuration to provide theshape shown in FIG. 7. Arms 204-207 are separated by channels 209, asdiscussed above.

FIG. 10 offers another view of the final configuration of the deliverypusher, with arms 204-207 extending from the distal end 202 of thepusher 200. Arms 204-207 extend in a radially expanded manner whenunconstrained, as shown in FIG. 10, in a manner that will be discussedin more detail later.

The distal part of each arm 204-207 has a hole 204 a-207 a, where eachhole passes completely through each arm. The function of these holes 204a-207 a is to hold a tether which connects to the occlusive device tothereby hold the occlusive device, as shown in FIGS. 11-13. In FIGS.11-13, the occlusive device 112 takes the form of an intrasacculardevice, intrasaccular devices were discussed in detail earlier. Theintrasaccular device can be a mesh comprised of metallic wires—made of,for instance, nitinol, stainless steel, and/or radiopaque material suchas tantalum, platinum, gold, or palladium. In another example,drawn-filled tubing, which comprises a radiopaque core materialsurrounded by a metallic (e.g., nitinol or stainless steel) jacket canbe used as part of the metallic mesh.

Arms 204-207 take on a first contracted configuration when housed withina delivery catheter, as shown in FIGS. 11 and 12. In FIG. 11, both thepusher 200 and occlusive device 212 are housed within a deliverycatheter 210 and therefore both have a contracted configuration. In FIG.12, pusher 200 is housed within a delivery catheter and has a contractedconfiguration, while the occlusive device 212 is freed from the deliverycatheter and adopts its naturally heat-set expansile shape. The arms204-207 take on an expanded configuration when not constrained by thedelivery catheter, as shown in FIG. 13. The arms are heat set such thatthey naturally adopt an expanded shape when unconstrained. The arms canbe manufactured in a variety of ways to enable this heat set shape. Forinstance, the distal part of the pusher can comprise a series oflongitudinal cuts spaced around the periphery of the pusher (e.g. 3 cutsspaced 120 degrees apart—as shown in FIG. 8, which would result in fourarms)—although fewer or more arms can be used. After the cuts are made,a material which has a larger diameter than the rest of the pusher iswedged into the distal arm region 102 of the pusher to expand thediameter such that the arms protrude outward, and the pusher isheat-treated or heat-set into this shape such that the arms adopt thisheat-set shape. The pusher can be made of a variety of materials,however, easily heat-set material such as nitinol is generally preferredat least along the distal region 202 so that the arms 204-207 can easilyadopt an expanded shape. In one example, a marker band (e.g. tantalum orplatinum) can be placed along a distal portion of the pusher to aid invisualizing the distal part of the pusher so the user can tell when theocclusive device is about to be delivered when utilizing fluoroscopicimaging.

In one embodiment, pusher 200 is a tube with a lumen therein, and thelumen provides a passage for additional materials to be tracked throughthe pusher. These additional materials can be additional embolic agents,and/or a detachment mechanism to dissociate the occlusive device 212from the pusher 200 to thereby deploy the occlusive device at thetreatment site. The detachment mechanism concept is shown in FIGS.14-15.

In FIG. 14, pusher 200 includes a lumen which spans the entirety of thepusher and is sized to accommodate a mechanical severing mechanism. Thesevering mechanism comprises an elongated rod 214 and a blade or knife216 at the distal end. Blade 216 is used to sever the tethers linkingthe occlusive device 212 to arms 204-207. This embodiment has particularutility for smaller sized intrasaccular devices (e.g. those used totreat neurovascular aneurysms) where it can be hard to design anon-mechanical (e.g. thermolytic or electrolytic) detachment system dueto the limited space available. The elongated rod 214 is mechanicallypushed through the pusher 200 so that the blade contacts the tethers tosever the tethers and thereby release the occlusive device. Alternativeconcepts can utilize a plurality of blades (e.g. 2, 3, or 4 blades). Inone example, the number of blades corresponds to the number of tethers.

In FIG. 15, a thermal detachment system is shown. An elongated tube 218is pushed through pusher 200, the elongated tube 218 has a heater coil220 at its distal end. The elongated tube has a lumen running betweenthe proximal and distal end which provides passage for a pair of wires222 a, 222 b. These wires are proximally connected to a voltage source(e.g., a battery) and distally connected to the heater coil to power theheater coil. The tube 218 is pushed through the delivery pusher 200 sothat the heater coil is placed near the tethers connecting the occlusivedevice to the arms. The heater is then activated to melt or sever thetethers, thereby detaching the occlusive device.

The specification disclosure has dealt with embolic deliverydevices/systems/methods and ways to make embolic delivery easier. Thespecification has also discussed particular utility for these conceptswith smaller occlusive devices (e.g. those used in theneurovasculature). Please note, these concepts can be sized eitherlarger or smaller to treat a variety of conditions in a variety ofregions of the vasculature, not necessarily limited to the neurovascularspace—in other words, these ideas can be used in a variety of regions inthe vasculature to facilitate easier embolic usage and delivery.

Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. Accordingly, it is to be understood that the drawingsand descriptions herein are proffered by way of example to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

What is claimed is:
 1. An occlusive delivery device for delivering anocclusive device through a delivery catheter comprising: a deliverypusher configured to deliver the occlusive device; the occlusive devicecomprising one or more wires and having a collapsed configuration whenwithin the delivery catheter and an expanded configuration when notwithin the delivery catheter; a connection interface linked to both thedelivery pusher and the occlusive device, the connection interfacefacilitating operative connection between the delivery pusher and theocclusive device so that the delivery pusher pushes the occlusivedevice; wherein the one or more wires of the occlusive device contactthe connection interface but are not attached to the connectioninterface, such that the one or more wires of the occlusive device canmove independently relative to the connection interface.
 2. Theocclusive delivery device of claim 1, wherein the occlusive device is anintrasaccular device comprising a mesh of wires.
 3. The occlusivedelivery device of claim 1, wherein the connection interface is a ring.4. The occlusive delivery device of claim 1, wherein the connectioninterface has one or more cut-out regions to allow the connectioninterface to flex.
 5. The occlusive delivery device of claim 1, furthercomprising a retention structure connected to both the connectioninterface and the occlusive device.
 6. The occlusive delivery device ofclaim 5 wherein the retention structure is one or more coils.
 7. Anocclusive delivery device for delivering an occlusive device through adelivery catheter comprising: a delivery pusher configured to deliverthe occlusive device; the occlusive device comprising one or more wiresand having a collapsed configuration when within the delivery catheterand an expanded configuration when not within the delivery catheter; aconnection interface between the delivery pusher and the occlusivedevice, the connection interface facilitating operative connectionbetween the delivery pusher and the occlusive device so that thedelivery pusher pushes the occlusive device; wherein the one or morewires of the occlusive device are linked to the connection interface butare not attached to the connection interface, such that the one or morewires of the occlusive device can move independently relative to theconnection interface.
 8. The occlusive delivery device of claim 7,further comprising a retention structure connected to both theconnection interface and the occlusive device.
 9. The occlusive deliverydevice of claim 8, wherein the retention structure is one or more coils.10. The occlusive delivery device of claim 8, wherein the retentionstructure is one or more rotatable bands.
 11. The occlusive deliverydevice of claim 10, wherein the one or more rotatable bands contain oneor more holes accommodating the one or more wires of the occlusivedevice.
 12. The occlusive delivery device of claim 8, wherein theretention structure is one or more holes in the connection interface.13. The occlusive delivery device of claim 12, wherein the one or moreholes in the connection interface accommodate the proximal ends of theone or more wires of the occlusive device.
 14. The occlusive deliverydevice of claim 12, wherein the retention structure is a plurality ofholes, and the one or more wires of the occlusive device pass throughtwo or more of the plurality of holes.
 15. An occlusive delivery devicefor delivering an occlusive device through a delivery cathetercomprising: a delivery pusher configured to deliver the occlusivedevice; the occlusive device comprising one or more wires and having acollapsed configuration when within the delivery catheter and anexpanded configuration when not within the delivery catheter; aconnection interface linked to a distal portion of the delivery pusher,the connection interface facilitating operative connection between thedelivery pusher and the occlusive device so that the delivery pusherpushes the occlusive device; wherein the one or more wires of theocclusive device are operatively connected to the connection interfacebut are not attached to the connection interface, such that the one ormore wires of the occlusive device can move independently relative tothe connection interface.
 16. The occlusive delivery device of claim 15,wherein the connection interface is a ring.
 17. The occlusive deliverydevice of claim 16, wherein the connection interface ring is attached tothe delivery pusher at one or more regions around the ring.
 18. Theocclusive delivery device of claim 15, wherein the occlusive device isan intrasaccular device comprising a mesh of a plurality wires.
 19. Theocclusive delivery device of claim 15, wherein the occlusive device isan intrasaccular device for occluding an aneurysm.
 20. The occlusivedelivery device of claim 15, wherein the occlusive device is anintrasaccular device for occluding a cerebral aneurysm.